Electronic devices, such as enclosures, are used by being installed in a supporting member, such as a rack or a locker. For example, signal wires and power wires between the electronic devices are generally connected by cable connection using a backboard or by connection using a rear connector board. This makes it possible to increase the functions of the electronic devices. As a proposal for such a connection, the proposal discussed in Japanese Laid-open Patent Publication No. 11-261264 is known.